The present invention relates to the use of a mobile modem/phone combination to provide a signal path to a land-based unit at a remote location as a local call that is then re-routed over a non-public switch telephone network to the land-based unit.
It is known to activate a wireless data terminal by connecting a mobile terminal such as a notebook computer or personal data device to a specialized mobile modem. The mobile modem has associated wireless mobile telephone capabilities or a separate mobile phone to which it is connected and acts as a mobile data unit, sometimes simply known as a mobile unit. Communication between the mobile unit and a land-based terminal such as a desktop computer connected with a hard-wired modem with a fixed phone number can then be made by using switched-circuit connections, created by using the mobile unit to dial the fixed number located on the public switch telephone network (xe2x80x9cPSTNxe2x80x9d) associated with the hard-wired modem. Thus, the current art requires one hard-wired modem and one hard-wired telephone circuit per land-based terminal.
In a hard-wired telephone network a specific telephone number is associated with only one serving switch, located at a specific geographic location. In a wireless network a specific mobile number for a wireless mobile modem or mobile modem/phone combination acting as a mobile unit may be served by any single one of a vast number of available switches depending on the specific geographic location of the mobile unit at the time a call is made. Such portability of use is one of the basic hallmarks of wireless telephony.
In the present implementation of wireless networks, each mobile number is associated by both the wireless and hard-wired networks with a specific geographic home switch location. The home switch location includes a physical connectivity matrix and a stored program control section that houses the logic and algorithms necessary to control the connectivity. Associated with wireless switches is a collection of Radio Frequency (RF) channels, aggregated in multiple physical locations called cell sites across a specific area corresponding to a serving market and variously known in the United States under the designations MSA, RSA, MTA, and BTA depending on the FCC license.
A pair of entities known as the Home Location Register (xe2x80x9cHLRxe2x80x9d) and Visited Location Register (xe2x80x9cVLRxe2x80x9d) have been defined by the American National Standards Institute ANSI-41 standard, together with a set of protocols for communication between switches, which allows seamless roaming, or call delivery, to be made. In the present art, the VLR is associated with the wireless switch where a mobile unit is currently being served, and the HLR is associated with the switch where the mobile unit phone number xe2x80x9cresidesxe2x80x9d (the geographic location where all hard-wired originated calls will be directed before being routed to a wireless switch with which the mobile unit is in communication).
Typically, when the VLR and HLR are physically in the same location, the mobile unit is xe2x80x9cHomexe2x80x9d and is not roaming. When the VLR and the HLR are not in the same location and specialized protocols are not implemented to make the mobile phone act as if it were xe2x80x9chomexe2x80x9d, then the mobile unit is xe2x80x9croamingxe2x80x9d.
Phone calls from a mobile terminal to a land-based terminal can be completed while roaming only by a carefully orchestrated set of interactions between the HLR and VLR, all of which are described and defined by ANSI-41. ANSI-41 defines the HLR as a logically and possibly physically separate device from the actual switching matrix underlying the RF portion of the wireless network for the home location of the mobile unit. Similarly, the VLR is defined as a logically and possibly physically separate device from the actual switching matrix underlying the RF portion of the wireless network from which a mobile unit is currently being served. This physical separation, together with the Signaling System Seven (SS7) and the associated messages and protocols are existing underlying components utilized by the invention.
The mobile numbers associated with a mobile modem or mobile modem/phone combination acting as a mobile unit may be ones to which no physical geographic location have been assigned, or standard dialable numbers. The numbers will be placed in a HLR database by which they can be interacted with from the current VLR location by a mobile phone. The HLR used by this invention may be associated with a switch or have no associated switching matrix.
A mobile unit makes its presence known, either by Power-on Registration, Autonomous Registration, a Call Attempt or any other means. For the purpose of illustration, the mobile unit decides to make a call attempt to a known hard-wired modem connected to a land-based terminal. The request is made and it includes various pieces of information transmitted from the mobile unit to a serving switch connected to a base station usually located at the center of a geographical area defined as a cell site. The serving switch forwards the information to a local VLR. The VLR interacts with the HLR associated with the mobile phone for the purpose of reviewing the information and selectively obtaining authorization and feature/restriction data for serving the mobile unit. Issues related to appropriate authorization include, for example, whether billing payment is current or if the mobile phone has been reported lost or stolen.
The VLR provides the HLR with location information of the mobile unit 5 that may be based in part on a temporary local directory number (xe2x80x9cTLDNxe2x80x9d) allocated from a pool of numbers whose geographic base is the physical location of the visited switch in direct communication with the mobile data unit.
The HLR sends back to the VLR any characteristic or limitation placed on the mobile unit and selectively authorizes call completion. If a call is authorized, the call along with any appropriate restrictions is communicated by the local VLR to the serving switch, which in turn outpulses the approved number being called over the public switch telephone network (xe2x80x9cPSTNxe2x80x9d) to connect to a desired hard-wired modem.
Among the feature/restriction elements available for use by an HLR is a Single-Number, so-called xe2x80x9cHotlinexe2x80x9d restriction. When a Hotline restriction is placed on a mobile phone by its associated HLR, the mobile phone will be connected only to this number when any call attempt is made regardless of the dialed number. The switch containing the VLR routes the call via the public switched network to the Hotline number.
FIG. 1 illustrates the current state of the art for completing a long distance call from a mobile modem or a mobile modem/phone combination to a hard-wired modem in a remote location that corresponds to a long-distance call over the PSTN.
A mobile terminal 4 connected to a mobile modem or mobile modem/phone combination acting as a mobile unit 5 makes a call attempt to a land-based terminal 7 by way of a cell site 9 connected to a serving switch 11 connected to the cell site 9 by way of an internal connection 13. The serving switch 11 requests handling instructions over a connection 15 from the local visited location register (xe2x80x9cVLRxe2x80x9d) 17. The VLR 17 examines the telephone number and other identifying information from mobile unit 5 and registers profile information from the home location register (xe2x80x9cHLRxe2x80x9d) 21 associated with mobile unit 5 over a circuit 19 through one or more regional transfer points generally known as signal transfer points (xe2x80x9cSTPxe2x80x9d) 23. The HLR 21 authorizes, over a return circuit 25, the use of mobile phone/modem 5 to connect mobile station 4 to land-based terminal 7 by responding to the VLR 17 through the signal transfer point 23.
With appropriate authorization information, the VLR 17 replies over a circuit 27 to the switch 11 and authorizes the call. In turn, the switch 11 outpulses the dialed telephone number digits over a circuit 29 to the PSTN 31 and creates the required connection between the mobile terminal 4 connected to mobile unit 5 and hard-wire data unit 33 connected to the land-bed terminal 7. Thus, a data connection is finally established and the two end points 4 and 7 can communicate.
A key problem with the current state of the art is that there is a fairly significant fee charged for the use of the PSTN, particularly when long distance calls are being made. Moreover, data unit 33 must be associated with and physically connected to the land-based terminal 7 and physically connected to a pre-determined hard-wired landline.
In the improved telephone system of the present invention, a pool of geographically dispersed hard-wired data units such as modems are connected to an alternate network that is distinct from the traditional public switch telephone network. In a preferred embodiment, the alternate network is server controlled and uses the Internet protocol. A hard-wired land-based terminal is connected either directly or indirectly to the alternate network and may be accessed by means of the alternate network.
When a mobile data unit such as a mobile phone and modem combination connected to a mobile terminal such as a notebook computer initiates a long distance call to be connected to the land-based terminal, the signal information is sent to a serving switch of the wireless or mobile telephone system. The serving switch sends the signal information to a first register associated with a home location of the mobile data unit. The first register determines the authorization of the mobile data unit and also sends the signal information to a second register. If a long distance call has been requested by the mobile data unit, the first register determines a local number to use to access one of the hard-wired data units and substitutes the requested long-distance number with a local access number instead. The information is transmitted back to the second switch and used to set up the phone call made by the mobile data unit. When the phone call is made, access to the public switch telephone network is local. Once the mobile data unit is connected with the hard-wired data unit, the call is then carried through the alternate network to the land-based terminal unit, bypassing the public switch telephone network to the extent that a long distance charge would otherwise be incurred, and optimizing call delivery.
A further advantage of the inventive system is that it allows the local number determining algorithms associated with the hard-wired data units to exist outside of the terminal equipment, enabling rapid adaptation to changing network conditions to be made without reprogramming every mobile terminal.